Cancer is a complex and devastating group of diseases that kills one in five adults in developing countries. Although cancers arise from a wide variety of cells and tissues in the body, there are unifying features of this group of diseases. Cancer is predominantly a genetic disease, resulting from the accumulation of mutations that promote clonal selection of cells that exhibit uncontrolled growth and division. The result of such uncontrolled growth of tumor cells is the formation of disorganized tissue that compromises the function of normal organs, ultimately threatening the life of a patient.
Basic research designed to unravel the mechanics of carcinogenesis have revolutionized our understanding of the molecular nature of genetic changes that initiate tumor formation. Notably, specific genes have been identified that are frequently mutated in tumor cells. These genes regulate, for example, DNA damage repair, homologous recombination, cell cycle control, growth factor signaling, apoptosis, differentiation, angiogenesis, immune response, cell migration, and telomere maintenance. Thus, based on mutations in certain genes, it is possible to distinguish cancer cells from normal cells.
However, despite advances in our understanding of the genetic basis underlying cancer cell phenotypes, effective methods for treating cancer remain largely undiscovered. While chemotherapeutic agents are designed to kill or block tumor cell proliferation, chemotherapeutic agents are frequently unable to exclusively suppress upregulated activity of a particular protein in a tumor cell without deleteriously affecting necessary levels of protein activity in normal cells. In the case of metastasized cancer, current cancer treatments, such as chemotherapy and radiation, are generally ineffective.